Sewing machine



July 31, 1923. 1,463,325

J. KIEWICZ SEWING MACHINE Original Filed April 2'7. 1920 4 Sheets-Sheet 1 Fig.1.

John Kiewicg byiwdMxW Afiys July 31, 1923.

- 1.463.325 J; KIEWICZ I SEWING MACHINE Original Filed April 27. 1920 4 Sheets-Sheet 2 John Kiewicg ATIys.

July 31, 1923.

J. KIEWICZ SEWING MACHINE original Filed April 27, 1920 4 Sheets-Shee t 4 Patented July 31, 1923.

"FF-ICE.

:ronn KIEWICZ, OFBOSTON,jMASSACHUSETTS, essrenon. T THELREEGE BUTTON HOLE MACHINE COMPANY, or Bos'roN, MASSACHUSETTS, n ooRronArIoN or.

MAINE.

SEWING acrame.

Application filed; April 27, 1920, Serial No. 376,951. Renewed January 20,1922. Serial no. 530,725.

To all whom it may concern Be it known that 1, JOHN Krnwroz, a citizen of the United States, residing at Boston, county'of Suffolk, State of Massa- 5 chusetts, have invented an Improvement in Sewing Machines, of which the following description in connection with the accompanying drawing, is a specification like characters on the drawing representing like 10 parts.

This invention relates to two-threaded V tion on each buttonhole to. pull ofi from the source of supply a sufficient length of the under thread to ensure the proper formation of the first stitch of the next buttonhole', and in which the tension for the under thread is carried by the rotary turret. The

object of the present invention is to provide novel means for relieving the tension on the under thread at the time that said length is pulled'ofl so as to avoid any possibility of the under thread being broken during the pulling-off operation.

In order to give an understanding ofmy invention, I have illustrated in the drawin s a selected embodiment thereof which will now be described, after which the novel features will be pointed out in the appended claims. f

' Fig. 1 is a side view of a portion of a but. tonhole sewing machine having my improve- 40 ments applied thereto Fig. 2 is a front view with the overhangin arm omitted;

Fig. 3 is an underside view of the bed frame showing the turret in section;

Fig. 4: is a frontview ofthe turret with the underthread tension thereon and showing also the means for relieving the tension;

Fig. 6 is a plan View of a portion of the clamp-plate and bed frame showing the underthread pull-0E and cutter;:

Fig. 7 is a view similar to Fig, 6. showing the clamp-plate and cutter removed;

' r vide the desired friction. Fig. 5 is a section on the line 5+5, Fi 4;

. Fig.8 is a fragmentary view showing the manner in which thefpull-oif operates. V

I have herein shown my invention as it might be embodied in a buttonhole sewing machine of the well-knownReec'etype,

exemplifications of -whioh are found in United States Patent N0."1 ,188,942, June- 27, 1916, and No. 1,406,742, Februarylath,

1 In the drawings, 1 indicates the bed frame of abuttonholesewingmachine of the above-- mentioned type whichis provided with ways 2 in which the work-holding means is slidably mounted, the latter comprising ,a clampplate 3 and work-clamps eplvote'd' thereto.

Thebed-plat'e 1 has the usual arm or head 5. r sing'the refrom which supports a reciprocating needle-bar 6 carrying the needle"? that'controls the vupper'thread 8. -The under-thread 9 is manipulated'by an underthread mechanism carried by a turret'lO which is rotatably mounted in the depending portion 11 of the frame, all as usual in I sewing machinesof this type.

This under-thread 'mechanisrn'is of the type usually employed in' sewing "machines 01 this character,'and it comprises an oscillating under-needle 12 which operates through the usual throat-plate 13 carried by the turret, a looper 14 which is actuated to take theloop of. upper-thread and hold it while the under needle 12 inserts the un: der thread through said loop, and a :tension 'device15' carried by the turret through which the under thread passes on it's way to the needle. y l

' The turretjcarries the usual-hollow spin dle'16 through whichlthe underthread 9 passes on its travel to 'theiten sion 15 and which is vertically movable to actuate the 20 between which the thread is led, and one of which is acted on by'a spring 21 to pro The machine herein shown is also prothe usual type comprising two friction disks vided with means operating on the under thread between the throat-plate '13 and the needle 12 for pulling off a length of thread 7 from the source of supplyto the tension 15 at the end of each-buttonh'ole,fthereby pro ,source of supply. The pull-off lever 22 is normally'held in the full :line position, Fig. 7, by a spring 25, and at the end of the stitching operation on a. buttonhole, the outer end thereof is acted upon by an actuating lever 26 which is pivoted to the bed frame at ;84 and which operates to swing the pull-oil lever into the dotted line position, Fig. 7, thereby carrying the hooked end thereof beneaththe throat plate and intowp'osition so that the under thread 9 will drop behind the hook.v When the pull-off lever has been moved into this position it is released and the spring 25 returns it to the full line'position thus causing the hook to form a bight in the underthread 9 between the throat-plate and the under needle 12 thereby pulling a length 01'? under thread from the source of supply. The swinging of the; pull-off lever into the full line position carriesthe'hook beneath a clamping plate 27 so that the thread is clamped between the hook and the clamping plate. After a length of under thread has been pulled off and clamped,'the under thread is trimmed close to the work and between the latter and the throat-plate by a trimming knife 28 which is pivoted to the clamp plate 3 at 29, and which is provided with shearing edge 30 that co-operates with the shearing block 31 to sever the under thread. This cutting V knife is normally held in full line position by a spring 61, and it is given itscutting movementby thelever 26. The constructionis such that the initial-movement of the actuating lever 26 operates the pullbii lever 22' and then releases it, while the final movement of said actuating lever hen operates the cutter 28. 7 During the initial movement of the lever 26 from. its full line position Fig. 7 to just beyond the dotted line posi tion a, the end of: said lever wipes by the end of the pull-off lever and a ctuates the latter, and then releases it, and atthis time a. projection 32 on said actuatinglever 26 is brought against a shoulder 33 on the cut ter so that further movement of the lever operates the cutter. This mechanism for actuating the cutter and the pull-off is shown and described more in detail in Patent No. 1,406,742. 7

The lever 26 isactuated at the proper time .by means of a roller 35 carried by an arm 36 which is rigid with the usual'feed cam 39 by which the work-holding means is given its feeding movement.

When the pull-oil lever 22 operates to draw of? a length of under thread, such length is pulled through the tension 15, and ii the thread is of a. poor quality,'or if the tension is considerable, there is'a: possibility that the thread may become broken. To obviate this, i have provided a novel means for relieving the tension on the under thread at the time that the pull-off lever actuates, and I propose to accomplish this herein by. a tension-releasing device which is actuated by the lever 26. livo-tally mounted on the turret is a tension-releasing member ST said member being pivoted to the turret at 38 and having at its upper edge a wedge-shaped portion which is. adapted to be forced between the tension disks 20 there by to separate 'them. This tension-releasing member 37 is acted on by a spring 58 which normally tends to hold it in inoperative position with a projection40 thereon resting against the inside'oit the portion 41 of the turret. This is the position oi' the tension releasing-member during the stitching on a buttonhole. When the buttonhole is completed and the parts arein, position i'or the pull ofl to operate, the turret will be turned into the position shown in Fig. 2 with the tension on the back side thereof.

The depending portion 11 of the frame has a lover 4-2 pivoted thereto at 43, one arm 44 of said lever having a cam surface 45 on its under. side which is acted upon by the lever 26 as the latter is given its actuating movement. The other end 46 oisaid lever is in position to engage the upper eiid oi the tensioirreleasing member 37. The eiid 4601" said lever is shaped so that when the turret arrives at the position shown in'EigsJZ-and 4 at the end of the stitching operatiointhe tension-releasingmember 37 will be situated opposite said end 46 and, "therefore, if the arm 44 of said lever is raised, the endE-46 will engage the tension-releasing member and swing it to the left Fig.4, thus separating the tension disks and relievingthe tension on the under thread. The parts are so constructed 'that during the "actuating movement of the lever 26','it engages the cam surface 45 of the lever 42,"thus causing said lever to actuate the tension-releasingmember 37, and the tension is 'thusreleased'while the under thread is being pulled off. "As a resultpthe underthread is free f om tension while it is being pulled off fand"there is'no danger of itsbe'co'ming brokend'u'eto a heavy tension thereon.

I claim: Y J I 1. In a two-threadsewing machine of "the type adapted to .sew a short seam "and then come to rest, the combination with aframe, or work-l1olding means carried thereby,

, an actuating lever for actuating said means to give a feeding movement to the work-holding means, a rotary turret mounted in the frame and carrying the underthread mechanism, a tension for the under thread carried by the turret, means to pull off a length of under thread through the tension at the end of each sewing operation, and means actuated thereby to release the tension on the .under thread while such length is being pulled off.

2. In a two-thread sewing machine of the type adapted to sew a short seam and then come to rest, the combination with a frame, of a rotary turret carrying the under-thread mechanism, a tension for the under thread carried by the turret, a pull-off device to pull ofi a length of under thread through the tension at the end of each sewing operatiolili, P off device, and means actuated thereby to release'the tension for the under thread.

3. In a two-thread sewing machine of the type adapted to sew a short seam and then come to rest, the combination with a frame, of work-holding means movably carried thereby a rotary turret carrying the under threadmechanism, a tension for the under thread carried by the turret,'a pull-0E lever pivoted to the frame for pulling off a length of under thread through the tension at the end of each sewing operation, a tension-releasing member, and means common to said pull-oil lever and tension-releasing member to actuate them both.

4:. In a two-thread sewing machine of'the type adapted to sew a short seam and then come to rest, the combination with a frame,

of a rotary turret carrying the under thread mechanism, a tension for the under thread carried by the turret, a pull-ofi' lever for pulling off a length of under thread through the tension at the end of each sewing operation, a tension-releasing member, an actuatname to this specification.

thread also carried by the turret, a tension- I releasing member pivoted to the turret, a lever .plvoted tothe frame, a second lever actuated thereby, and adapted to engage the tension-releasing member to release the tenslon forthe under thread.

6. In a sewlng machine, the comblnation with a frame, of work-holding means car ried thereby, a feed cam for giving feeding movement to said work-holding means, a rotary turret carrying under-thread mechanism, a tension for the under thread carried by the turret, a lever pivoted to the frame, means associated with said feed cam for ac tuating the lever, and means actuated by the lever to release the tension and lengthof under thread.

pull off a 5 7. In a twothread'sew ing nachine of the type adapted to sew a short seamand then come to rest, the combination with a frame, of work-holding means carried thereby, stitch-forming mechanism including a rotary turret mounted in the frame and carrying the under-thread mechanism, means for giving. the worleholding means and stitchforming mechanism a relative movement, a

tension for the under thread carried by the turret, means separate from the first-named means to pull oif .a length ofunder thread 7 through the tension at the end of each sewing operation and means actuated thereby to release the tension on the under thread while such length is being pulled off.

In testimony whereof, I

JOHN KrEWIoz;

have signed my 

